In a virtual computer system, one or more virtual computers (hereinafter referred to as a “virtual computer”) can be constructed on one physical computer (hereinafter referred to as a “physical computer”). The virtual computer systems is capable of independently operating an OS (Operating System) on each of virtual computers (sometimes referred to as an LPAR (Logical Partition)). Thus, a plurality of OSs may be operated on one physical computer.
A live migration technology is known in which data constituting a virtual computer on a certain physical computer is made to migrate to a virtual computer on another physical computer in a state where the virtual computer is in operation in a virtual computer system (PLTs 1 and 2).